Compared to HC, nuclear NF-κB p65 was increased in patients with SP-MS and PP-MS; T cells from all MS subgroups and monocytes from PP-MS showed a higher nuclear p65 proportion than those from HC; the p65 DNA-binding activity in unstimulated PBMC was greater in SP-MS and PP-MS compared to HC. Here, NFKB1 is linked to myeloid sarcoma.